In the processed meats industry techniques are known for the automatic and semiautomatic filling of various types of casings with viscous meat emulsion to make smaller sausage products such as frankfurters and the like, and more recently, due to advances made in the technology, the larger sausage products such as bolognas, salamis, liverwursts, and the like, which had traditionally and customarily been made by unautomated essentially manual procedures. In general, these techniques include positioning a shirred continuous film casing length over a stuffing horn and thereafter continuously deshirring and stuffing the deshirred casing with viscous meat emulsion fed under pressure through the stuffing horn and into the casing interior. As used herein, the term casing or tubular casing is intended to mean tubing of natural or manufactured materials, and the term "casing length" is intended to mean continuous tubular casing lengths. Shirred tubular casings are known to persons familiar with the art as "sticks", such "sticks" being long lengths of casing which have been shirred and compressed into short, compact self-sustaining lengths, or which may be a shirred and compressed casing sheathed inside an over fitted retaining sleeve or wrapper. Apparatus and processes are well known in the food casing art for producing shirred tubular cellulosic food casings such as, for example, the apparatus and processes disclosed in U.S. Pat. Nos. 2,983,949 and 2,984,574 to Matecki. Smaller casing sticks are sometimes packaged together into unitary package articles, such as shown, for instance in U.S. Pat. No. 3,764,351. Until fairly recently, the shirred form of casing was available in only smaller diameter sizes for making frankfurter or the like linked form sausage products, the larger sausage production techniques involving the use of cut lengths uf unshirred casings. There are however, not available to industry, shirred forms of the larger casings for making bologna and similar larger products, such casings as described, for instance in U.S. Pat. No. 4,007,761. Using suitable food stuffing machinery, casing lengths of either the smaller or larger diameters are stuffed and formed into unit size links of particulate or comminuted viscous materials, meat emulsions, or the like, to make frankfurters and similar smaller products or, as the case may be, bologna and the like larger products.
In the art of producing sausages and similar food products, the finely divided meat compositions, commonly referred to as emulsions, are conventionally stuffed into tubular casing materials of long length which, as stated above, may be of natural or manufactured materials. Large sausage products which are sliced for multislice package putup are usually made in casings which range in size from the trade designation #21/2 (73 mm. diameter) to #12(170 mm. diameter). In the production of large sausage products, a shirred casing length, clip-closed on one end and open on the other, is sheathed over the end of a stuffing horn on a stuffing apparatus and then stuffed with a food emulsion. As the stuffing operation progresses, the clip-closed end of the casing moves outward of the stuffing horn and the casing itself deshirrs and eventually reattains its original length, or a length substantially close to its original length. The stuffed casing is tied, or clip-closed into predetermined unit length cylindrical sausage products as the stuffing progresses until the entire length is used up, at which time, emulsion flow is shut off and a new shirred casing length is placed on the machine.
The thusly stuffed and encased food emulsion is subsequently cooked and cured according to one or the other of conventional processes, depending on the product being made, and may thereafter be, and, in the case of the larger diameter products, usually is, sliced and packaged into units of predetermined weight and slice count for retail sale.
For many years, the apparatus and methods employed to prepare such encased food products, particularly food products encased in large diameter casings, have relied largely if not exclusively on manual manipulation in controlling the stuffing of food emulsion into predetermined length sausage links or packages. The casings used with these earlier types of stuffing apparatus were furnished in precut unshirred lengths which had to be presoaked before being placed on the stuffing horns. Recent advances in the art have provided apparatus for greater automation of stuffing operations in production of the larger diameter sausage products and have provided means for preparing uniformly sized larger products with precision, speed, consistent reproducibility and reliability in manufacture comparable to, and heretofore only experienced in, the technique of the smaller sausage products manufacture. Of particular interest in this regard is the U.S. Pat. No. 4,044,426.
An automatic sausage casing stuffing technique such as that illustrated in U.S. Pat. No. 4,044,426, involves the combination of a sizing ring or disc arranged and disposed inside the casing being stuffed, coacting with an annular snubbing ring arranged and disposed exteriorly of the casing a selectably variable distance along the casing length from the sizing ring. The sizing ring has an outer rim circumference greater than the inner circumference of the casing, and the annular snubbing ring has an inner passage circumference smaller than the outer circumference of the finished sausage product being made. Both the sizing disc and the snubbing ring are disposed in coaxial alignment with the stuffing horn of the sausage making machine, and provision is made to controllably vary the linear distance between the sizing disc and the snubbing ring.
By lessening linear distance between the sizing disc and the snubbing ring the change in the path of casing moving from its stretched circumference as it deshirrs over the sizing disc, to its proscribed circumference as it passes through the space between the stuffing horn outer surface and the inner passage circumference of the snubbing ring, becomes more abrupt and increased frictional forces at the areas of casing contact with these control elements will increase a braking or holdback action on the casing. Conversely, by increasing the linear distance between the sizing disc and the snubbing ring, the change in the path of the casing between these two casing contacting elements becomes less abrupt, effecting a decrease in frictional forces at the casing contact areas with a consequent decrease of braking or holdback action on the casing. Thus, for a given and reasonably closely maintained set of operating parameters, including type and condition of casing, consistency of the emulsion, emulsion pump speed and output pressure and, say the parts wear condition of the stuffing apparatus, an increased holdback force on the casing will tend to cause higher casing internal pressure and a larger product circumference, while decreased holdback force on the casing will lessen casing internal pressure and make for a smaller product circumference.
Since the desideratum is to maintain a constant product circumference, suitable for the automatic slicing, weighing and packaging procedures which follow, the linear distance between the sizing disc and the snubbing ring is controllably changed to compensate for variations and aberrations in the other aforedescribed operating parameters which are not so easily controlled.
Thus, since the above-described stuffing operations inherently involve casing internal pressure, it is possible from time to time to experience a casing failure such as from a break or weak spot in the casing. It is also possible to experience a clip or tie application failure. Both such occurences result in squirting out of the emulsion, with attendant loss of product, emergency shut down procedures, clean up, and lost production time. In the days when the stuffing techniques were somewhat less automated and slower, casing breaks and clip failure were not as great a casue for concern, because the stuffing operator, of necessity, was always at his post right at the stuffing machine, hand feeding the casing off the stuffing horn, and could thus effect the necessary shut down procedures promptly upon the occurence of any malfunction. With the present day high speed and more automated machines and processes, however, the operators are not always immediately within the range of access to the controls, and a casing break or clip failure can cause extremely troublesome results, especially in the stuffing of the larger sausage products since the emulsion volumes in process are so much greater than the volumes comprehended in smaller sausage product manufacture.